Evan, Alexa

Following the preparation described in alog 15524, we made a ringdown measurement of both the x- and y-arm. For each arm, we locked the IR beam and ran the wfs to ensure maximum build up. We then turned the wfs off, and switched the input polarity of the MC common mode board to unlock the MC quickly (based on LLO's alog 11727 the MC has about a 15usec ringdown time). We used the relfected signal at the AS port to capture the ringdown. We repeated this measurement 10 times to have ample data for our uncertainities. We also measured the "off-resonance" ringdown, by unlocking the arm and misaligning the respective ETM. All the data can be found in /ligo/home/alexan.staley/Public/Ringdown/EX(Y)data (these folders are then split into locked and unlocked times).  From this data we calculated the total loss:

X arm: 14310(100) ppm

Y arm: 15000(100) ppm

Based on the galaxy ITMY transmissivity (1.42%) this amounts to 800ppm of loss in the y-arm. Meanwhile, for the x-arm, the ITMX transmissivity is 1.39 % corresponding to a 410ppm loss in the arm. We are in the process of calculating the transmissivity of the ITMs based on our ringdown fit. Our code can be found in /ligo/home/alexan.staley/Public/Ringdown/proccess.py. The y-arm losses seems consitent with our scan measurements; however the x arm does not. These numbers are very sensitive to the transmissivity we use; so before we make an conclusion with this we should inprove our confidence in the transmissivity values.

Dave O, Elli, Kiwamu

We have improved the dynamic range of the scatter pictures we took last night.  We did this by:

-Changng analog gain on the camera from 1023 to 100.

-Changing from 8 bit to 12 bit enconding

-Averaging over 100 images rather than just using one.

We now have a much clearer picture of scattering off of ETMy.  We took an image of ETMy with IR locked and green misaligned.  We then subtracted a background image with both green and IR misaligned.  We plotted the images using log10 of the intensity.  We have also included the same image plotted with linear intesnity, which can be compared directly to last night's image. 

Daniel was seeing problems running excitations to the ISC EY integrators, but at the time was not seeing the same problems at EX. We restarted h1iscey to restart its awgtpman. Problems persist at EY and now EX is seeing intermittent excitations. We'll take a closer look tomorrow. This is not a filtermodule excitation channel, rather an excitation part in the model.

Evan and Alexa working on ringdown measurements
Daniel and Dave changing h1iscex and h1iscey models
Jim W. and Krishna working on seismic sensor correction

07:25 Jeff and Bubba moving 3IFO storage containers in the LVEA
07:32 Karen and Cris into the LVEA
08:57 Filiberto and Aaron cabling in the LVEA
09:16 Corey and Kiwamu to the squeezer bay
09:16 Filiberto to end Y to look at the illuminator and dust monitors
09:35 Jim W. and Krishna to the CER
09:46 Jim W. and Krishna back
09:56 Karen cleaning at mid Y
10:19 Dave to mid X to label racks
10:48 Karen leaving mid Y
10:54 Dave back
11:55 Bubba, Jeff and Andres done 3IFO work in the LVEA. LVEA is back to full laser hazard.
12:00 Filiberto and Aaron done
12:36 Kyle and Gerardo taking engine hoist from corner station to end Y
13:14 Cyrus to mid X, end X and end Y to work on surveillance cameras
14:20 Kyle and Gerardo done
Cyrus done

J. Warner, K. Venkateswara

The LLO sensor correction was implemented at the rest of the test mass chambers, after installing it yesterday at ETMX. Plots are attached.

There is a significant difference in performance between chambers despite the CPS sensors showing about the same level of subtraction (~10). ETMY_Y shows only a factor of 2 improvement at 0.43 Hz, while ITMX shows  the full factor of 10 improvement. We are not sure why this is the case yet, but we'll look linto the isolation loops tomorrow.

All outdoor and indoor units are on site. Indoor units are all hung and refrigeration lines are being connected. Outdoor units will be set next week after the concrete pad is poured. Partition wall is up and sheet rock in place, taping and paint next week. 

Evan and I found the ETMY and ETMX back to the distributed configuration and no longer in offloaded. Based on a dataviewer trend this got switched  12/09/2014  18:34 UTC. I have reverted them both back.

Kyle, Gerardo 

Moved engine hoist into VEA 

~1340 - 1345 hrs. local -> Ran purge air compressors to confirm that 1 psi regulator was regulating at 1 psi

Bubba G. Andres R. & Jeff B. 

   This morning, after placing a 4" wafer in the center of the container, we sealed the 3IFO Storage container #3 and moved it into its long term storage location. The C3 cover over the suspensions was arranged so as to allow free N2 circulation, (see photos below).   

   Storage Container #2 was moved into the loading position and the cleanroom was moved back into place. The container is ready to accept the last group of suspension for storage.

   The six suspensions (the last of the SUS/TMS suspensions from the staging building) that were staged by the High-Bay door were also craned over the beam tube. These are the bulk of the suspension to be loaded into Storage Container #2.      

Daniel, Patrick, Dave

we restarted h1iscex and h1iscey with Daniel's latest code. The DAQ was then restarted.

SheilaD, JimW, HugoP,

We updated the SEI Guardian on site. The update only impacts the BS chamber. It is a patch that allows switching the GS13s to low analog gain when in ST2 is DAMPED. The GS13 are switched back to high analog gain when ST2 is ROBUST_ISOLATED. This update was applied to prevent the ISI from tripping during 'kicks' of the BS, which are inherent to the commissioning tasks. Update details can be found in SEI aLog #662

JimW's WP can now be closed.

Hugo

I've made a simple change to the sus guardian.  The impact will be that after the guardian changes the alignment of an optic, it sets the ramp time for the alignment slider back to a short time (2 seconds).  This is a more convient ramp time when people are fine tuning alingments, this will just save us from always changing the ramp time by hand after we use the guardian.  

The only changes to the code were to add one line ( line 301) at the end of the main of get_alinging_state

susobj.alignRampWrite(susconst.shortRampTime)

and to add a new parameter to susconst.py

shortRampTime = 2

Although this changes the ramp time setting before the first ramp has finished, the first ramp still finishes with the five second ramp time that was set when it started.  If anyone wants to change the time for a particular optic that can be done in the same way that the ramp time for TMS was set to be 10 (look at the TMS guardian). I've committed the changes to SUS.py. which we are using an h1 version of, but not susconst since we are using a common file

K. Venkateswara

After the changes to the way BRS is used at ETMX, detailed in 15497, tilt-subtraction shows significant improvement. Attached files show ASD plots from 40k seconds of data from last night, when winds were barely a few mph at ETMX.

The first plot is in angle units.  The blue line shows the ground seismometer output, the green shows the raw BRS output and the red curve shows the new tilt-subtracted super-sensor output. The roll-off at 5 mHz is due to the high-pass filter but most of the other difference is from the new tilt-subtraction. This is also clear in the coherence plot shown below - the coherence between the super-sensor and the T240 is less than the coherence between the T240 and BRS. The BRS ref is shown in cyan.

The tilt-subtracted super-sensor is tilt-free and reliable till ~30 mHz or so. Why is this important? For one thing, it can be used to do sensor-correction to Stage 1 of the BSC-ISI, while keeping tilt-reinjection at a minimum. This has the effect of reducing the microseism, which is a big problem at LLO and will be a problem here as well. This was shown recently in 15498.

Seismic:
Evaluation of tilt correction on all platforms as available

Suspensions:
Dan H. working on OMC tip/tilt

CDS:
Cabling for illuminators

Optical levers:
Installation of weights on optical lever piers

Facilities:
Contractors will be pouring concrete tomorrow. Access to the Y arm will be restricted until Monday morning.

3IFO:
Next to last BSC ISI is in its container, ready for exchange of containers

Alexa, Evan

We want to perform some ringdown measurements of the arms (particularly the Y arm) in order to corroborate our other loss measurements. We intend to use the technique described by Isogai et al., which has already been carried out at LLO (see, e.g., LLO#13748, LLO#11727).

In preparation, we've done the following work:

• We have placed a PDA255 on ISCT6, in front of ASAIR_B (since it is currently unused). The dc bandwidth of ASAIR_B is supposed to be 100 kHz, which is fine for observing the power decay (which probably has a ~2 ms time constant), but may not be fine for observing the initial power spike.
• In front of the PDA255 there is a 28 mm lens in order to provide a smaller spot size for the PD.
• Cyrus has paired the LVEA scope (TDS3038, I think) with a wireless router. With Chris's script for grabbing data from the scope, we should be able to take ringdown measurements comfortably from the control room.

Tomorrow we'll try to take some data and analyze it.

These instruments have just been sitting on thefloor with no insulation so Krishna Jim and I got them under Trillium igloos.  We had trouble with the internal Cable routine and may revisit to improve that.

Evan, Krishna, Alexa, Dan, Kiwamu,

At some point in this evening, we noticed that the IMC kept dropping its lock for some unknown reason. It turned out that the HAM2 ISI sensor correction was amplifying seismic at 0.3-ish Hz which resulted in a large drive in MC2 to keep it locked. So we turned the sensor correction off for now. This fixed the issue.

Even though the MC2 coil DACs were not saturating, somehow the motion was big enough to unlock the IMC. It is still unclear why it could unlock. Anyway, after turning off the sensor correction, the amont of drive in MC2 suspension reduced by a factor of 5 or so and IMC became able to stay locked. With the sensor correction on, the MC length was moving approximately +/- 5 um according to IMC_X displacement monitors. We don't know what changed in the HAM2 ISI sensor correction as it has been running fine for a while recently. Only thing we immidiately noticed was that the seismic freq-limited RMSs were pretty high in 0.1-0.3 Hz and 0.03-0.1 Hz bands in this evening. The attached is a time series of the IMC_X signals when we did a simple test of turning on and off the sensor correction in the HAM2 ISI. Since we were a bit rough for turning on and off the correction, it gave a transient when switcing it, but one can still see that when the correction was running, the IMC_X signal increased by roughly a factor of 5.

SudarshanK, TravisS, EvanH, AlexaS, RickS

Using the Pcal beam localization cameras at both end stations, we took images of the ETM surfaces under three conditions: IR and Green resonating; IR only resonating, and Green only resonating.

Attached below are two composite images composed of four separate images taken with the same camera settings:
Upper Left: Xarm Green
Lower Left: Xarm IR
Upper Right: Yarm Green
Lower Right: Yarm IR

The images in the first composite were taken with the following camera settings: F8, ISO 200, 30 second exposure, WB-cloudy.

For the second composite image the aperture was F29 (~13 times less light)

The Yend camera was re-focused for the IR-only images, but the Xend camera was not re-focused.

Travis/Betsy

This morning, we staged to put the ETMy QUAD monolithic structure back together.  We vacuumed as much of the structures as we could.  I re-first-contact-cleaned the ERM-front surface since it had been exposed to the elements since the last vent and showed much particulate dispite blowing it with N2.  The FC cleaning worked and the surface looked improved.  We then removed the ETMy test mass HR First contact (which has been on since it left CIT) and attached the 2 lower structures.  Using the Genie, w transfered the completed lower structure to the silver pallet jack + 5-axis lift table.  We then maneuvered the LS into place and attached it to the upper structure already on the ISI table.  We removed all of the lifting EQ from the QUAD and stowed everything in the unused welding cleanroom.  All went well.  We did not suspend the QUAD - we'll start that on Monday.